A fluid dynamic bearing device is a bearing device which rotatably supports a shaft member through an oil film formed in bearing gaps. The fluid dynamic bearing device has characteristics such as high-speed rotation operation, excellent rotational accuracy, and quietness. In recent years, by taking advantage of those characteristics, the fluid dynamic bearing device is suitably used as a bearing device for a motor to be mounted to various electrical apparatuses such as information equipment. Specifically, as a bearing device for a motor, the fluid dynamic bearing device may be suitably used in the following: a spindle motor for an information apparatus such as a magnetic disk drive such as an HDD, an optical disk drive for a CD-ROM, CD-R/RW, DVD-ROM/RAM, or the like, or a magneto-optical disk drive for an MD, MO, or the like; a polygon scanner motor of a laser beam printer (LBP); or a fan motor.
Of the above-mentioned motors, in particular, in the spindle motor for a disk drive, contamination due to oil (lubricating oil) can not be tolerated at all in terms of its product properties. Under the circumstances, in the fluid dynamic bearing device incorporated in the spindle motor, for the purpose of preventing leakage of lubricating oil filling the inside of the bearing, a seal portion is commonly provided to an opening portion of a bearing member (housing) so as to form a seal space in which the lubricating oil is retained with use of a capillary force. Further, in order to prevent the leakage of lubricating oil more reliably, on an end surface of the seal portion, which is exposed to external air, an oil-repellent film containing a fluorine resin or the like is provided in some cases (refer to Patent Documents 1 and 2, for example).    Patent Document 1: JP 2004-176815 A    Patent Document 2: JP 2006-292013 A